Good Evening fellow Jeepers, i have a 93 ZJ with the 5.2 and i am working on switching out the CPS, i found a video that shows a different way to get to the CPS, long story short for this to work, you need the heat shield off, when i went to take off the 3 bolts that holds the heat shield in place, i got to the one that closest to the fire wall and came to realize that there is a lock nut on the inside of the heat shield and im having a bit of time trying to get it off and figuring out what size the lock nut is. It should obviously be the same size as the one on the outside right????

 

If it's a fiber locknut, it may be the next size larger.

If it's a 1/4" thread, it'll have a 7/16 head and the locknut will be 1/2.